A gas turbine engine has various components, e.g., fasteners, plugs, etc., that unless restrained can loosen and disengage due to vibration. Consequently, it has for many decades been a standard practice in the engine industry to install a supplemental restraining device such as lock-wire to prevent such components from loosening. There are various types of lock-wire, including but not limited to types referred to as safety wire and Bergen cable.
Even though lock-wire has been used for many decades, the installation of lock-wires remains time consuming and difficult. A single engine may have hundreds or thousands of components that require lock-wire. To avoid having the lock-wires cause obstruction or injury during assembly of the engine, the lock-wires are installed after the components have been attached to the engine. A mechanic uses a manual to determine the part numbers and the locations of the components that require lock-wire. The mechanic must then locate the components and install the lock-wires. However, most of the components on the engine are metallic or gray in color and thus visually blend together, thereby making it difficult to locate the components that require lock-wire. Furthermore, a number of the components that require lock-wire are underneath the engine or behind other components and thus not readily visible.
The inspection of lock-wires is also time consuming and difficult. Inspections are traditionally performed to determine whether lock-wires are installed on all of the components requiring one. However, in the course of the inspection, the inspector must locate each component that requires lock-wire using the same procedure as that used by the mechanic who installs the lock-wires.